Space Quest: The Lost Chapter is an unofficial fan-made game that takes place in the Space Quest universe as created by Sierra. The story takes place between Space Quest II and Space Quest III, and sees Roger Wilco starting the game in the escape pod in which he finished Space Quest II. The game is faithful to the characters and events of the original series, but forges its own story. It ends in a position that leads directly into the opening of Space Quest III.

The graphical style of The Lost Chapter is similar to that of Space Quest II, with cartoony 16-color graphics. The game is a standard 3rd-person adventure with keyboard control and a text-based parser. Similar to its official Sierra counterparts, this game features innumerable ways to die.